The N-methyl-3,4-dimethoxyphenylethylamine, also known under the name of N-methylomoveratrylamine, is an intermediate useful in the synthesis of a drug having coronarodilator activity, internationally known as verapamil (INN), described in the U.S. Pat. No. 3,261,859.
The synthesis of the N-methylomoveratrylamine was described both in patent documents like the unexamined japanese publication JP 77036606, the german publication DE 3338681 and the european publication EP 0233766 and in scientific publications, for instance in J. Med. Chem. 16, (6), 630-3, (1973), in J. Am. Chem. Soc. 104, (3), 877-9 (1982) and in J. Org. Chem. 52, (7), 1309-15, (1987).
In the japanese publication, the N-methylomoveratrylamine is obtained by reducing the corresponding amide by means of a mixture made by an organic acid and by sodium borohydride.
In the german publication, the veratrylcyanide is catalytically hydrogenated, by using a nickel catalyst, in the presence of a strong molar excess (10:1) of methylamine.
In the european publication EP 0233762, the N-methylomoveratrylamine is obtained by acylating the omoveratrylamine with methyl chloroformate and then by reducing the so obtained compound by means of a molar excess of lithium aluminium hydride in anhydrous tetrahydrofuran.